A network of ground sensors, such as unattended ground sensors, may make use of wireless sensor networks for surveillance applications. For example, the network of ground sensors may be used in wooded zones where surveillance using radar systems is not viable.
A network typically includes battery-powered devices that use various sensors to monitor physical properties or environmental properties, such as temperature, seismic waves, or magnetic fields, to detect movement of pedestrians and vehicles. The ground sensors send data via a wireless network to a base station that processes the data provided by each ground sensor.
Typically, unattended ground sensors are sophisticated and intelligent devices. Each sensor receives data and processes the data to identify events corresponding to passage of a pedestrian or a vehicle and possibly even to discriminate between different types of events (e.g., a pedestrian event, a light vehicle event, a heavy vehicle event, etc.) and/or to determine a position of the pedestrian or the vehicle. Consequently, each sensor may be relatively expensive. In addition, a size of the sensors is relatively large and the sensors are designed for long endurance in a semi-permanent deployment. Thus, much effort may be required to plan the deployment.
There is a need for a relatively simple unattended ground sensor that may be conveniently deployed, such as from the air.